Vibration

[Yam350]

The other day I rode my v11 about 50miles in a “spirited fashion” on a mixture of roads. It ran great with no issues. It was left overnight before setting off again, however about 10 minutes into the trip I noticed an increase in vibration and a very slight hesitancy from closed to open throttle. This hesitancy was very subtle and wasn’t noticeable at higher revs. On inspection there was nothing obvious and I continued home. The vibration remained but didn’t get worse. I’ve had look today and found the rear bevel box bearing was worn allowing it to move (I’ve got another thread about that) however looking at the bearing it’s been like that for a while so probably not the cause of the vibes. I owned this bike about 5 years ago and just recently bought it back. It’s lived a bit since I last owned it but seems mechanically sound and up until now was surprisingly smooth. Any thoughts would be much appreciated. 

[MartyNZ]

Is the vibration felt in the bars or foot pegs? How long since the cylinders were synchronized?

[docc]

Along with a throttle body synch (and, perhaps, the full Decent Tune-up), inspect the rubber throttle body connections to the intakes for leaks or looseness/ "popped off" as well as inspecting the various sensor electrical connectors that one has not come unplugged.

While you're inspecting, look at the various exhaust junctions for anything loose or leaking . . .

[Yam350]

It was more noticeable in the bars, and seemed to come on very quickly. I’ve since replaced the rear wheel bearings along with the bevel box needle roller which was completely shot, but obviously that wouldn’t account for the change in fuelling. I guess I’ll have to go through the whole thing. I actually owned this bike about 5 years ago and went through it all then. It’s lived a life since then but up until now I was pleasantly surprised how smooth it was. I’ve got the tank off and everything looks ok, although the air and fuel filters look like they’re the ones I fitted. Just a thought I’d  filled up with petrol a few miles before the issue started…..is it possible that muck has been dislodged and caused a partial blockage in the filter. The bike had been unused for a while before I bought it.

[audiomick]

4 hours ago, Yam350 said:

…..is it possible that muck has been dislodged and caused a partial blockage in the filter. The bike had been unused for a while before I bought it.

I reckon that is a possibility that you shouldn't ignore without investigating it.

[LowRyter]

hesitation and vibration could be tps.  

[audiomick]

I suppose it is also vaguely possible that you got a bad tank of fuel. You'll know better yourself if the petrol station in question might be sloppy enough to have bad fuel in the pump.

[80CX100]

On 7/1/2023 at 4:52 AM, Yam350 said:

It was more noticeable in the bars, and seemed to come on very quickly. I’ve since replaced the rear wheel bearings along with the bevel box needle roller which was completely shot, but obviously that wouldn’t account for the change in fuelling. I guess I’ll have to go through the whole thing. I actually owned this bike about 5 years ago and went through it all then. It’s lived a life since then but up until now I was pleasantly surprised how smooth it was. I’ve got the tank off and everything looks ok, although the air and fuel filters look like they’re the ones I fitted. Just a thought I’d  filled up with petrol a few miles before the issue started…..is it possible that muck has been dislodged and caused a partial blockage in the filter. The bike had been unused for a while before I bought it.

Once I started long hard rides,on my new to me 2003 Lemans; the bike suffered severe tank suck issues.

The symptoms can vary from subtle & sublime,to sudden & severe like mine.

After the first long hard ride & refueling while out on the roads;I had a violent release of tank vacuum pressure when I opened the lid on the gas tank to add fuel.

My bike would hardly run for the ride home;

While your tank is off,verify the two vents under the cap(guitar strings are perfect to use) & the lines that attach to them are open & verify the routing of the plumbing.

A PO had plumbed my tank vent lines through a T fitting into the vacuum fittings on the throttle bodies.

I eliminated the T & re-routed my lines open to atmosphere & capped the vacuum ports at the TBs.

The bike now runs perfect.

fwiw ymmv good luck

ps While you're looking at it & because it's a known to cause problems,verify the wire bullet plug connections for the clutch switch on the left side of the frame/steering head.

 

[Yam350]

Thanks, I’ll check out the vents. 

[motoguzznix]

Hi Yam

 

I would also stick with the latest fuelling.

My friends Quota did not enjoy fuelling up with Diesel. 

But regarding your problem: you may get some grid into with the new fuel or maybe water. Grid should remain in the fuel filter, water can go through it and cause misfires. Drain the fuel tank, renew the fuel filter and fill in clean gasoline. 

[gstallons]

BTDT , I topped of my Suzuki (about1 1/2 gallon of diesel ) and did it show , I didn't think I would get home . Drain & refill and it eventually started .

[audiomick]

Diesel in petrol motor is not good, but I think we all know that. An  anecdote from my youth: on King Island, that is between mainland Australia and Tasmania, about 36000 gallons of diesel got pumped off the delivery ship into the petrol storage tank at the dock. Somehow no-one noticed until it had destroyed several motors on the island.

 

but that is way off topic...

[ScuRoo]

26 minutes ago, audiomick said:

Somehow no-one noticed until it had destroyed several motors on the island.

 

but that is way off topic...

King Island you say?

Generally takes a few generations before noticing there may be a problem occurring 

Creams a bit thick 😁

[audiomick]

A mate of mine in the first couple of years at boarding school came from King Island. I was there a couple of times during the holidays.

 

But that is even further off topic...